Terminations for high voltage (i.e., greater than about 12 kV) polymeric insulated electrical transmission cables are typically accomplished by cutting back an outer polymeric jacket, neutral conductors, a semiconductive layer, and a primary polymeric insulation layer to expose a primary conductor, on which an electrical connector is installed. The exposed components of the cable must be protected. For high voltage cables, such protection typically requires electrical stress control at the termination and various stress control elements have been provided for this purpose.
Stress control elements may be based on high permittivity polymers (refractive stress control), slightly conductive polymers (resistive stress control), combinations of those, or a combination of conductive and insulating polymers (geometric stress control). Cover systems including polymeric heat shrinkable tubes with metal-oxide filled mastics (e.g., Uniterm IXSU/OXSU or HVT-Z termination accessories from TE Connectivity termination accessories available from TE Connectivity) have been used to form stress controlled terminations and capitalize on the high permittivity and the non-linear electrical behavior of metal-oxide powders. Covers have also been provided including flexible cold shrink tubes including metal-oxide powder embedded in an elastomeric matrix.
Range taking cable termination accessories are often preferred because they reduce required inventory.
Self-supporting, dry cable terminations are often preferred over liquid-filled or flexible terminations.